Safety officials are stepping up pressure on the Federal Aviation Administration to require video cameras in cockpits so accident investigators will have better information on what causes plane crashes.

The confusion and lack of effective training about how to deal with fires shocked federal accident investigators, who say in interviews and public records that fires remain a serious threat to passenger aircraft.

Part of Alligator Alley, one of two routes crossing the Florida Everglades, was closed when smoke from a 3,000-acre brush fire cut visibility to zero. The 60-mile stretch of Interstate 75in the middle of the state was closed at about 9 p.m. Tuesday night. Troopers didn't know when it would reopen.